Much lower quality of LDR vs HDR in Render Target.

[Opamp77]

I had to do this myself in 4.7.6.
Assuming your happy compiling from github.

You would find need to add a bool property to USceneCaptureComponent within USceneCaptureComponent.h.

UPROPERTY(EditAnywhere, Category = SceneCapture, meta = (DisplayName = “Disable Tonemapper”))
bool bDisableToneMapper = false;

and within the FScene::CreateSceneRenderer() function within SceneCaptureRendering.cpp
after the

if (bCaptureSceneColour)
{
ViewFamily.EngineShowFlags.PostProcessing = 0;
ViewInitOptions.OverlayColor = FLinearColor::Black;
}

add

if (SceneCaptureComponent->bDisableToneMapper) {
ViewFamily.EngineShowFlags.SetTonemapper(false);
}

If you now disable the tonemapper on the scenecapturecomponent with LDR(with post-process) enabled you will get HDR with post-process.

Edit* the other option is to set your post-process to happen after the tonemapper if possible.
I however was in a situation where this was’nt possible.